Transcript Blood Vessels

Blood
Blood is a specialized connective
tissue: cells are suspended in liquid
matrix called plasma
• Functions
Transport – substances to and from cells in
body
Regulate – temperature, acids, bases, salts &
water
Protection – vs. disease or loss of fluid via
clotting mechanism
Components
Plasma: ~90% water. Contains cells,
nutrients, cellular waste, immune factors
and proteins.
Plasma proteins: albumin, globulins, fibrinogen
Red Blood Cells [erythrocytes]: transports
oxygen via hemoglobin
White Blood Cells [leukocytes]: immune
function
Platelets[thrombocytes] clotting
mechanism
All blood cells are derived from the same stem cells in the bone
marrow. Depending on body needs, they will differentiate into
specific cells.
Red Blood Cells
• More 600-700x more numerous than WBCs
• 17x more numerous than platelets
• Once mature, lose their nuclei, and interior
area is occupied by hemoglobin molecule.
• Hemoglobin contains iron – which binds
onto oxygen molecule
Oxygenated hemoglobin = oxyhemoglobin
Deoxygenated hemoglobin = deoxyhemoglobin
White Blood Cells
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Neutrophils
Basophils
Eosinophils
Monocytes
Lymphocytes: B&T
• Develop in bone marrow
– mature in spleen and
thymus
• Phagocytes: neutrophils,
eosinophils, monocytes
Blood Clotting /coagulation
• Injury to tissue causes release of chemicals that
initiate clotting mechanism
• Process requires ~30 different proteins called
clotting factors
• Calcium is required for this process
Circulatory System: Blood Vessels
Blood Vessels
Arteries – carry blood away from the heart
Veins – carry blood towards the heart –have valves
Capillaries – vessel that allows exchange with tissues
[ 60,000 miles in adult]
Structure of vessels
• Outermost layer – tunica externa/adventitia –
dense connective tissue – primarily collagen
• Middle layer – tunica media –muscle layer,
also has elastic connective tissue
• Innermost layer - tunica interna – epithelium
called endothelium [special name for epithelial
tissue of this system]
• Hollow area where blood travels =lumen
Pulses
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Carotid
Temporal
Radial
Brachial
Abdominal
Femoral
Popliteal
Dorsalis Pedis
Tibialis
Blood Pressure measures the volume of blood
Read by using a sphygmomanometer [BP cuff] and
stethoscope
Record first distinct sound as systolic number [systolic BP] –
contraction of heart/how hard the heart is working
Record the last distinct sound as diastolic number [diastolic
BP] heart at rest/ the resistance of blood by the vessels – how
dilated or constricted they are.
‘Normal’ = <120/<80
Hypertension = high blood pressure 140/90
Hypotension = low blood pressure
2. Make sure patient is comfortable, and
limb is supported. Put cuff on limb
just above the antecubital crease.
3. Inflate the cuff to approx. 180 mg Hg,
and slowly deflate.
1. Choose a BP cuff
that is the proper
size, which depends
on the
circumference of the
limb
4. Listen for first distinct sound –
mentally note number, and last
distinct sound – noting number.
5. Be sure to completely deflate cuff
when done, and remove from arm.
Lowest blood pressure is in the R atrium of heart
Hypertension
• Today roughly 65 million Americans have high
blood pressure and another 45 million have prehypertension.
• Americans spend more than $15 billion each year
on drugs to treat hypertension
• The 2005 Dietary Guidelines for Americans
recommends that young adults consume less than
2,300 mg of sodium per day. People with
hypertension, African Americans, and middle-aged
and elderly people—almost half the population—
are advised to consume no more than 1,500 mg
per day.
Source CSPI